Knee Surgery – Procedures
The knee joint is a highly complex mechanical structure, which can be damaged by mechanical forces or disease. Joint preservation in the latter case pertains to the hematological domain of countenance of the autoimmune pathological process of cartilage destruction. In most cases however, arthritis is the final stage of joint mechanical erosion due to excessive forces on attenuated cartilage. The strategies to preserve the joint focus on repairing the mechanical balance of the joint forces to avoid concentrated loads. Structures, which protect the joint cartilage, include the collateral ligaments, the cruciate ligaments and the meniscal pads. Cartilage transplants, meniscal allografts, and complex ligamentous reconstruction are all possible treatment options.
Knee arthroscopy is a minimally invasive procedure that allows for minor repairs to the soft tissue components of the knee. Some examples include: trimming or repair of the meniscal weight bearing pads, buffing of scuffed articular surfaces, removal of floating bodies (bone chips), or reconstruction of the cruciate ligaments. It is ideally suited for healthy or minimally arthritic joints. Because it is minimally invasive, arthroscopy offers many benefits to the patient over traditional open surgery: minimal incision and scarring as well as a faster recovery and return to regular activities. In the presence of concurrent arthritis however, knee arthroscopy is usually contraindicated, as the degenerative process is already set in motion and can actually be worsened by any intervention, even if well intentioned.
Frequently, the damage sustained to the knee involves mostly only one compartment or area of the knee. In that case, the patient may be a candidate for a partial knee replacement. The major advantage is the preservation of key ligaments, which preserves optimal balancing and function to the joint. The success rate of this operation depends on proper patient selection and technical accuracy. Dr. Meere strongly believes in the superiority of robotics and guided surgery for such delicate cases. It is important for the patient to realize that though function is best with a partial knee replacement, longevity of the implant is not as high, since the patient remains highly active and wear of the implant and non operated compartments will take its toll. Revision of the partial knee replacement or conversion to a total knee replacement may be necessary after 5-10 years.
This technique is a further refinement of computer assisted surgery. In addition to visual feedback as in a GPS navigation system, the pioneering science of haptics allows for direct robotic instrumentation by means of a mechanical arm, handled by the surgeon and based on a virtual model created by a preliminary CAT scan of the knee. A virtual firewall or electronic fence boundary ensures both accuracy and safety. Mako Corp. has developed this application for knee surgery. The technology is currently available for partial or double-partial knee replacements. The superior accuracy of the instrumentation afforded by this technique is very promising and should yield much improved function and durability for partial replacements
With advancing years or mechanical damage from sports or accidents, the complex and sophisticated multi-axial knee joint can develop arthritis, defined as the erosion of the cartilage buffer zone between the bones forming the articulating joint. When the pain, stiffness and loss of mobility are no longer tolerable, the patient becomes a candidate for a knee replacement. In this routine procedure, the worn out cartilage cap at the end of the bones forming the knee are trimmed and chamfered to allow for insertion of a metallic cap and tray articulating with one another through a highly resistant low friction plastic (polyethylene) cartridge insert. The patient satisfaction success rate of the operation is high, but is critically dependent on diligent post operative cooperation with exercises and physiotherapy.